1. Field of the Invention
The present invention generally relates to large scale operating systems and more particularly relates to enhancements for accommodating maintenance, administration, and control.
2. Description of the Prior Art
Large scale data processing systems are well known in the data processing art. Such commercial systems have been in general use for more than 30 years. Some of the most successful large scale data processing systems are available from Unisys Corporation.
One of the great advantages of such large scale systems is the availability of software libraries. These libraries are collections of software programs offering a wide diversity of functionality. Because these systems are relatively large, the corresponding library collections can become very large. The HVTIP (High Volume Transaction Internet Processing) library available from Unisys Corporation accommodates up to 16,383 different library programs. Each addition to the library represents one or more functions available to subsequent users without the need to ever again code and debug the script needed to provide that function(s).
Techniques for handling libraries tend to be a function of the library size. As the size of the library increases, different methods are required to produce acceptable efficiencies. U.S. Pat. No. 6,101,533, issued to Brandt et al; U.S. Pat. No. 6,108,692, issued to Van Seters et al; and U.S. Pat. No. 4,181,937, issued to Hattori et al each discuss various aspects for handling on-line libraries.
Whenever the control console of the system needs to access the libraries for periodic maintenance or system updates, the libraries must be locked out from access by any applications. Obviously, accesses cannot be permitted, particularly when system repair and regeneration is in process. Therefore, if the libraries were simply to be listed on the maintenance console or printed on the maintenance console printer, the libraries can be unavailable to calling applications for an extended period of time.
If all user accesses to the libraries are prohibited during control console access (as is required during maintenance sessions), the libraries become unavailable for however long it takes to complete the maintenance task involving the system console library access. This wait time is further lengthened to the extent that the maintenance programs which utilize the libraries are accorded a priority which is lower than other occurrences within the system. On the other hand, it can become highly inefficient to always grant highest priority to certain maintenance tasks which may be routine in nature.
Thus, with a potential library having in excess of 16,000 separate programs, simply listing them on a printer from a routine maintenance program operating in the demand batch mode can effectively tie up the entire system for an inordinate period of time.